Please understand that this setup is quite complex; it's multidisc (previous XvT installation not required) and works with volume labels (BALANCE, XWVSTIE1). You'll be prompted for the XvT CD when necessary.

It's been quite tedious to overcome a few obstacles:

writing NiftyZip as done in the first place with XvT and bugfixing/refining it with BoP

upgrading an existing XvT installation (done by uninstalling the old version first)

dealing with the large folder of extracted BoP files and laying everying out accordingly

getting the few missing files/folders from the original XvT CD

It's astonishing how well the game seems to work under Vista x64 - without any compatibility modes (they even make it unplayable on my machine).